repeat action by sets of 100 items max in selection

X-Raym_Repeat action by sets of 100 items max in selection.lua

--[[
 * ReaScript Name: Repeat action by sets of 100 items max in selection
 * Screenshot: https://i.imgur.com/nQsH3mL.gif
 * Author: X-Raym
 * Author URI: 
 * Repository: 
 * Repository URI: 
 * Licence: GPL v3
 * Forum Thread: 
 * Forum Thread URI: 
 * REAPER: 5.0
 * Version: 1.0
--]]
 

-- USER CONFIG AREA -----------------------------------------------------------

console = true -- true/false: display debug messages in the console
action_id = 65535 -- integer or string like "_RS58e79379a72978b5be7ee39118af7b78b949dd08"

undo_text = "My action" 
------------------------------------------------------- END OF USER CONFIG AREA


-- UTILITIES -------------------------------------------------------------

-- Save item selection
function SaveSelectedItems(t)
  local t = t or {}
  for i = 0, reaper.CountSelectedMediaItems(0)-1 do
    t[i+1] = reaper.GetSelectedMediaItem(0, i)
  end
  return t
end

function RestoreSelectedItems( items )
  reaper.SelectAllMediaItems(0, false)
  for i, item in ipairs( items ) do
    reaper.SetMediaItemSelected( item, true )
  end
end


-- Display a message in the console for debugging
function Msg(value)
  if console then
    reaper.ShowConsoleMsg(tostring(value) .. "\n")
  end
end

function Main_OnCommand( val )
  if not tonumber(val) then
    val = reaper.NamedCommandLookup(val)
  end
  reaper.Main_OnCommand( val, 0 )
end
--------------------------------------------------------- END OF UTILITIES


-- Main function
function Main()
  sets = 0
  reaper.SelectAllMediaItems(0, false)
  for i, item in ipairs(init_sel_items) do
    reaper.SetMediaItemSelected( item, true )
    if i % 100 == 0 or i == #init_sel_items then
        Main_OnCommand( action_id )
        reaper.ShowMessageBox("Items " .. sets * 100 .. " - " .. i , "Info", 0)
        reaper.SelectAllMediaItems(0, false)
        reaper.UpdateArrange()
        sets = sets + 1        
    end
  end

end


-- INIT
function Init()
  -- See if there is items selected
  count_sel_items = reaper.CountSelectedMediaItems(0)
  if count_sel_items == 0 then return false end

  --reaper.PreventUIRefresh(1)

  reaper.Undo_BeginBlock()

  init_sel_items = SaveSelectedItems()

  Main()

  RestoreSelectedItems(init_sel_items)

  reaper.Undo_EndBlock(undo_text, -1)

  reaper.UpdateArrange()

  --reaper.PreventUIRefresh(-1)
  
end

if not preset_file_init then
  Init() 
end